simplify common chunk logic

[tdhock]

this is a follow-up to #238 with more test cases and simplified implementation.

[tdhock]

• HEAD=optimize-common stopped early for getCommonChunk improved in #238
  

Generated via commit e635216

Download link for the artifact containing the test results: ↓ atime-results.zip

Task	Duration
R setup and installing dependencies	2 minutes and 23 seconds
Installing different package versions	14 seconds
Running and plotting the test cases	3 minutes and 27 seconds

[tdhock]

[ FAIL 4 | WARN 0 | SKIP 0 | PASS 1267 ]

══ Failed tests ════════════════════════════════════════════════════════════════
── Failure ('test-renderer1-WorldBank-NA.R:57:3'): chunk1 contains expected columns ──
sort(names(chunk1)) not identical to sort(c("xmax", "group")).
Lengths differ: 3 is not 2
── Failure ('test-renderer1-WorldBank-NA.R:74:3'): common chunk contains expected columns ──
sort(names(common)) not identical to sort(expected.cols).
Lengths differ: 7 is not 8
── Failure ('test-renderer3-NA-separate-lines.R:37:3'): three <path> rendered for highlighted San Marcos ──
length(hilite.list) not equal to 3.
1/1 mismatches
[1] 1 - 3 == -2
── Failure ('test-renderer3-NA-separate-lines.R:42:3'): three <path> rendered for selected San Marcos ──
length(path.list) not equal to 3.
1/1 mismatches
[1] 1 - 3 == -2

[codecov]

Codecov Report

❌ Patch coverage is 97.41379% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.73%. Comparing base (d6e41e6) to head (e635216).
⚠️ Report is 21 commits behind head on master.

Files with missing lines	Patch %	Lines
R/uu_zzz.r	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #242       +/-   ##
===========================================
- Coverage   95.36%   77.73%   -17.63%     
===========================================
  Files           1      164      +163     
  Lines        2781     8812     +6031     
  Branches      560      562        +2     
===========================================
+ Hits         2652     6850     +4198     
- Misses        129     1962     +1833     

Flag	Coverage Δ
javascript	95.37% <100.00%> (+0.01%)	⬆️
r	69.56% <95.31%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.